They are kept inside the vault (don´t really know where), and
when you choose to see the drawing in pdf format, pdmworks extracts
them to a temporary directory defined in the PdmWorkgroups
settings.
The PDF's are stored on the server, under the VaultData Folder. Go
to the project you checked the drawing in, under the folder called
the Revision, you should find it there.
BE CAREFUL in the VaultData, if you screw something up in there,
you could have problems.
They are kept inside the vault (don´t really know where), and when you choose to see the drawing in pdf format, pdmworks extracts them to a temporary directory defined in the PdmWorkgroups settings.